Large diameter pipe of the type employed to transport gases and liquids under pressure typically are made with flanges on each end with "O" ring seats, i.e., hemispherical annular seating grooves, cut into the face of each flange. To seal two pipe sections together to provide a tight leakproof seal, an "O" ring is placed in the seats cut into the complementary faces of the flanges of the two pipe sections to be joined. When the flanges are sealed by bolting the flanges together, the "O" ring is compressed to provide a tight, leakproof seal.
This method of joining flanged pipe sections does not present unusual difficulties where the pipe sections are to be assembled above ground and in good light. Serious difficulties are encountered, however, when the above-described method must be employed to join pipe sections together under water as in laying pipe to deliver oil or gas from off-shore wells to on-shore gathering facilities. As can be readily visualized, visibility in such work locations is poor. Moreover, surface wave action frequently causes the support vessel to surge. The movement of the support ship tends to move one or both of the flanges, which in turn may cause slippage of the "O" ring. The incidence of hand injury suffered by divers assembling pipe lines is high by reason of a tendency of divers to hand hold an "O" ring in the desired position while another pipe section is being moved into proper position to seal the flanged sections of pipe together.
Accordingly, there is a serious need in the art for improved tools and methods for seating an "O" ring in a seat defined by seating grooves cut into complementary sections of flanged pipe.